In a wheel machining process, an expanding and shrinking device is used widely, for example, an improved machining center clamp of which the patent number is CN 201470924 U is introduced, the device consists of a power lock and a tightening core, however, the device has the problems of simple structure, short service life, small expanding and shrinking stroke range and the like, meanwhile, aluminum skimmings easily enter an opening of the power lock, and therefore, the machining precision is affected. The invention introduces a high-precision large-stroke tensioning device.